1. Field of the Invention
This invention relates to cushioning materials and is more particularly concerned with a box spring and mattress combination.
2. Description of the Prior Art
The very strict requirements of federal, state and local fire codes for mattresses and related materials used in institutions such as hospitals, hotels, detention establishments and the like and in maritime vessels, aircraft and the like, are now such that mattresses and or box springs, fabricated from materials hitherto conventionally used, are no longer acceptable for such uses.
Various forms of fire retardant mattress have been reported. For example, U.S. Pat. No. 3,512,192 describes the preparation of a mattress in the form of a laminate of a plurality of layers of polyurethane foam separated by layers of fiber glass.
Very recently there have been described flexible polyurethane foams which are capable of passing the tests established for the uses set forth above; see U.S. Pat. Nos. 3,738,953 and 3,909,464. The principal such tests are the Hot Bolt Test (Military Specification Mil R-20092F) and, more particularly, the Federal Flammability Standard for Mattresses DOC FF4-72. Unfortunately, while the foam itself will pass the necessary tests, it is found that, when said foam is fabricated as a mattress using conventional covering fabrics (i.e. ticking), or even using substantially non-flammable coverings such as fiber glass cloth, and is combined with conventional box springs, the resulting combination can cause a serious fire hazard. This is particularly so in the case of a fire which originates in the room in which the mattress and box spring combination is housed even though the fire may not originate within the latter combination itself. In such instances it is found that conventional mattress and box spring combinations, even those in which the mattress core is a flame retarded polyurethane or like foam, are capable of contributing significantly to the resulting fire and the toxic fumes generated thereby and may even facilitate spread of said fire.
I have now found box spring and mattress combinations which are substantially free of such hazards and which will pass the above, very severe, tests. These combinations are, accordingly, acceptable for uses of the type discussed above, as well as for domestic use.